How to test a scripted module

I modified the SlicerCaseIterator module, but I don’t actually know how to test/debug it.

the command i use is ~/tools/Slicer-4.10.0-linux-amd64/Slicer --additional-module-paths ~/build/slicer/SlicerCaseIterator/SlicerCaseIterator

but it fails to load which means there is an error, but I am not sure how get the errors to show up.
is there a better way beyond adding the --launcher-verbose option?

Any script errors on startup show up in the terminal and in the python console. Also if you start with a working module (like unmodified SlicerCaseIterator) and you enable developer mode (in the preferences dialog) then you can incrementally reload and debug the script.